Connect UserStyleSheetWatcher to FileWatcher to have changes to

Default/User StyleSheets/Custom.css instantly change layout in
all your tabs.

BUG=2393

Review URL: http://codereview.chromium.org/799005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@41561 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 34 insertions, 6 deletions

diff --git a/chrome/browser/user_style_sheet_watcher.cc b/chrome/browser/user_style_sheet_watcher.cc
index 2d3e945..2bc9568 100644
--- a/chrome/browser/user_style_sheet_watcher.cc
+++ b/chrome/browser/user_style_sheet_watcher.cc
@@ -9,6 +9,15 @@
 #include "chrome/common/notification_service.h"
 #include "chrome/common/notification_type.h"
 
+namespace {
+
+// The subdirectory of the profile that contains the style sheet.
+const char kStyleSheetDir[] = "User StyleSheets";
+// The filename of the stylesheet.
+const char kUserStyleSheetFile[] = "Custom.css";
+
+}  // namespace
+
 UserStyleSheetWatcher::UserStyleSheetWatcher(const FilePath& profile_path)
     : profile_path_(profile_path),
       has_loaded_(false) {
@@ -33,6 +42,12 @@ void UserStyleSheetWatcher::Observe(NotificationType type,
   registrar_.RemoveAll();
 }
 
+void UserStyleSheetWatcher::OnFileChanged(const FilePath& path) {
+  ChromeThread::PostTask(ChromeThread::FILE, FROM_HERE,
+      NewRunnableMethod(this, &UserStyleSheetWatcher::LoadStyleSheet,
+                        profile_path_));
+}
+
 void UserStyleSheetWatcher::Init() {
   ChromeThread::PostTask(ChromeThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &UserStyleSheetWatcher::LoadStyleSheet,
@@ -43,20 +58,20 @@ void UserStyleSheetWatcher::LoadStyleSheet(const FilePath& profile_path) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::FILE));
   // We keep the user style sheet in a subdir so we can watch for changes
   // to the file.
-  FilePath style_sheet_dir = profile_path.AppendASCII("User StyleSheets");
+  FilePath style_sheet_dir = profile_path.AppendASCII(kStyleSheetDir);
   if (!file_util::DirectoryExists(style_sheet_dir)) {
     if (!file_util::CreateDirectory(style_sheet_dir))
       return;
   }
   // Create the file if it doesn't exist.
-  FilePath css_file = style_sheet_dir.AppendASCII("Custom.css");
+  FilePath css_file = style_sheet_dir.AppendASCII(kUserStyleSheetFile);
   if (!file_util::PathExists(css_file))
     file_util::WriteFile(css_file, "", 0);
 
   std::string css;
   bool rv = file_util::ReadFileToString(css_file, &css);
   GURL style_sheet_url;
-  if (rv) {
+  if (rv && !css.empty()) {
     std::string css_base64;
     rv = base::Base64Encode(css, &css_base64);
     if (rv) {
@@ -68,6 +83,12 @@ void UserStyleSheetWatcher::LoadStyleSheet(const FilePath& profile_path) {
   ChromeThread::PostTask(ChromeThread::UI, FROM_HERE,
       NewRunnableMethod(this, &UserStyleSheetWatcher::SetStyleSheet,
                         style_sheet_url));
+
+  if (!file_watcher_.get()) {
+    file_watcher_.reset(new FileWatcher);
+    file_watcher_->Watch(profile_path_.AppendASCII(kStyleSheetDir)
+                         .AppendASCII(kUserStyleSheetFile), this);
+  }
 }
 
 void UserStyleSheetWatcher::SetStyleSheet(const GURL& url) {
diff --git a/chrome/browser/user_style_sheet_watcher.h b/chrome/browser/user_style_sheet_watcher.h
index 87fa5ce..14960a0 100644
--- a/chrome/browser/user_style_sheet_watcher.h
+++ b/chrome/browser/user_style_sheet_watcher.h
@@ -9,17 +9,18 @@
 #include "base/logging.h"
 #include "base/ref_counted.h"
 #include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/file_watcher.h"
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 #include "googleurl/src/gurl.h"
 
 // This loads the user style sheet on the file thread and sends a notification
 // when the style sheet is loaded.
-// TODO(tony): Watch for file changes and send a notification of the update.
 class UserStyleSheetWatcher
     : public base::RefCountedThreadSafe<UserStyleSheetWatcher,
                                         ChromeThread::DeleteOnUIThread>,
-      public NotificationObserver {
+      public NotificationObserver,
+      public FileWatcher::Delegate {
  public:
   explicit UserStyleSheetWatcher(const FilePath& profile_path);
   virtual ~UserStyleSheetWatcher() {}
@@ -35,6 +36,9 @@ class UserStyleSheetWatcher
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
+  // FileWatcher::Delegate interface
+  virtual void OnFileChanged(const FilePath& path);
+
  private:
   // Load the user style sheet on the file thread and convert it to a
   // base64 URL.  Posts the base64 URL back to the UI thread.
@@ -42,12 +46,15 @@ class UserStyleSheetWatcher
 
   void SetStyleSheet(const GURL& url);
 
-  // The directory containing the User StyleSheet.
+  // The directory containing User StyleSheets/Custom.css.
   FilePath profile_path_;
 
   // The user style sheet as a base64 data:// URL.
   GURL user_style_sheet_;
 
+  // Watches for changes to the css file so we can reload the style sheet.
+  scoped_ptr<FileWatcher> file_watcher_;
+
   NotificationRegistrar registrar_;
   bool has_loaded_;